With the rapid development of display technologies, display panels having fingerprint identification functions have gradually become widespread in people's lives. At present, the fingerprint identification function is realized in display devices by means of, for example, the photosensitivity of PIN junction. A photosensitive sensing unit including PIN junctions can receive light reflected by a fingerprint so as to generate light current, and because of the difference in the intensities of light reflected by a valley and a ridge of the fingerprint, the generated light currents will be different, thus the valley and ridge of the fingerprint can be identified.